Ocate volcanic field


The Ocate volcanic field is a monogenetic volcanic field located in the eastern Sangre de Cristo Mountains of northern New Mexico. About 8.12 million years ago, basaltic volcanoes began to erupt in the Ocate area. Fourteen eruptive pulses have been recognized.
An unusual feature of the Ocate volcanic field is that the oldest basaltic flows form the highest mesas, and the youngest flows form surfaces lower in elevation. This reverse stratigraphy occurred because after the older flows were erupted about 8.3–5.7 m.y. ago on a relatively flat alluvial plain, the entire area was uplifted, and canyons were cut into the older basalt flows. Younger basalt flows then filled the major stream canyons. When uplift ceased, the youngest basalt flows of the Ocate volcanic field flowed on top of intermediate-aged flows.